Knotted cable attachment apparatus formed of braided polymeric fibers

ABSTRACT

A surgical, orthopaedic cable attachment apparatus and method for the surgical repair or fusion of orthopaedic anatomical structures is constructed from a length of flexible cable formed of a braided polymeric material having a first and second end portion. A first loop is formed in the first end portion of the cable with a second loop is formed, being placed around or through the bone parts to be tied. After the second loop is place around the selected bone parts, the free cable end is passed through the first loop and pulled tight to define a tightened position. The free cable end can have a needle. The free end is then secured to the cable by splicing for example, to hold the cable in the tightened position.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part of copending U.S. patent application Ser.No. 08/100,458, filed Jul. 30, 1993, which is a continuation of U.S.patent application Ser. No. 08/001,065, filed Jan. 6, 1993, nowabandoned, both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a surgical cable attachment apparatusand more specifically to a non-loosening, tensionable, knotted surgicalcable attachment apparatus formed of braided polymeric material and asurgical method of the fracture fixation, bone fusion and ligamentreattachment.

2. General Background

Surgical procedures for the repair or fusion of large and small bones,ligaments and tendons, and other orthopedic procedures frequentlyrequire use of an orthotic device or attachment apparatus which can besubject to tensioning and bear heavy loads caused by the uniqueanatomical features of the compromised bone or tendon. For example,fractures of the patella are exposed to high stresses during flexion andextension of the knee joint; fusions of the spinal vertebrae are exposedto high gravitational forces and movements of the spinal column; tornligaments and tendons are exposed to high stresses due to contraction ofthe associated muscle or flexion and extension of the bony structures;and trochanteric reattachment and cerclage techniques involve cable thatis tensioned and exposed to high weight loads and stress factors.

An orthotic or attachment device used in such a fashion must be able tobear heavy stress loads, be flexible enough to achieve the desiredrepair, and be sufficiently inelastic to maintain alignment of theanatomical structures for proper fusion and repair.

SUMMARY OF THE INVENTION

Materials currently available for such surgical procedures includesynthetic or wire sutures, metal cable and various specializedprosthetic or orthotic devices. Synthetic and metal sutures aresusceptible to fatigue and breakage during application and use. Thecurrently available synthetic suture materials have insufficientstrength and stiffness to provide the stress sharing and strain-limitingcapabilities required. Metal cable or wire sutures, while providingadditional strength, lack the flexibility required for many fusionand/or repair procedures, and are succeptable to breakage due tofatigue.

Satisfactory repair or fusion requires that the bones or bone fragmentsremain sufficiently immobilized to permit healing. Current proceduresfor the repair or fusion of small bones including vertebrae and thepatella, restrict motion of the bones or bone fragments by wiring theelements into the appropriate position. The applied surgical wire isgenerally bent tightly around the bone fragments and two ends of thewire are generally twisted together to provide compressive force.

Breakage of wire sutures or cables may occur with bending duringimplantation of the device or post-implantation movement generatingrepetitive bending stresses. Failure of the wire to supply sufficientcompressive force and apposition of bone fragments results in reduced orfailed healing of the bones. Sharp wire points caused by wire breakagein situ can result in significant damage to surrounding tissues and/orjoint capsules.

Metal suture material is radiopaque, and interferes with efficient X-raymonitoring of bone fusion and repair. Metal sutures also interfere withthe use of magnetic resonance imaging diagnostic procedures whichrequire that no metal be present in the vicinity of use.

It would be highly desirable to provide a small diameter, flexible, loadbearing suture to replace low strength polymeric or synthetic suturesand metal sutures for use in the fusion, repair, and augmentation ofsmall bones, ligaments, and tendons.

A material has been developed that has the unique properties of hightensile and fatigue strength, low stretch, high abrasion and cutresistance, and a high surface lubricity. This material is formed of ahigh strength, biocompatible, organic polymer, preferably polyolefins,such as high strength polypropylene or ultra high molecular weightpolyethylene which can be braided into a cable.

It has been found that a braided cable formed of strong polymeric fibersproduces a load bearing suture of sufficient tensile strength,flexibility and stiffness to be useful in the repair and fusion of smallbones, ligaments and tendons.

The polymeric braided cable of the present invention has strength atleast equivalent to that of a metal suture, and much greaterflexibility. The present invention does not exhibit the problemsassociated with metal fatigue and breakage of wire, and may be formedwith a much smaller diameter.

The polymeric braided cable of the present invention may also be formedof a bioresorbable polymer, eliminating the necessity of removing thecable and allowing gradual transfer of stress to the tissue or bone overtime.

The load bearing cable of the present invention has the followingcharacteristics: greater tensile strength than available polymericsuture materials; greater stiffness than available suture materials;greater flexibility and fatigue lifetime than metal sutures; transparentto x-rays and does not interfere with magnetic resonance imaging;tightly woven to discourage tissue ingrowth.

The load bearing cable of the present invention is formed of a pluralityof high tensile strength polymeric fibers, each of which is less than100 microns in diameter and has a tensile strength of greater than orequal to about 350,000 psi, and preferably greater than 500,000 psi. Toform the load-bearing cable, a plurality of such fibers are formed intoa hollow braid having a longitudinal bore extending through the center.The load bearing cable may be formed from as few as one ply or as manyas six ply bundles of approximately 120 individual fibers per ply.Preferred is a two-ply, eight strand braided cable preferably less than3 mm in diameter and most preferred is a one ply, eight strand braidedcable less than 1 mm in diameter.

It has been found that a cable attachment apparatus formed of thesefibers offers great potential in many orthopedic and non-orthopedicapplications as well as non-medical applications. However, thematerial's surface lubricity makes it difficult to tie a fasttensionable knot in the cable. Presently used knotting techniques forthe cable include back-to-back granny knots, however, these knotspresent a problem as the knots slip or break before less than 50% of thecable's strength is tensioned. Although this failure strength might beadequate given the anatomical loads of the body, surgeons need to beable to tension as well as hold fast the attachment apparatus in orderto provide an adequate union between tendons and ligaments, bonefragments and other bony structures in need of repair or fusion.

Therefore, it would be highly desirable to provide a knotted cableattachment apparatus constructed from a braided polymeric materialformed of ultra high molecular weight polyethylene.

The invention is directed to a cable attachment apparatus for thesurgical repair or fusion of bones, ligaments and tendons, and otherbony structures which can be subject to tensioning and heavy bearingloads. The invention is also directed to a method of forming the cableattachment apparatus with preferably non-loosening tensionable knots.The cable attachment apparatus can be used in both medical andnon-medical applications.

In one embodiment the cable attachment apparatus is constructed from alength of flexible cable having first and second ends, by forming afirst non-self-loosening knot in a first portion of the cable to createa relatively large adjustable loop. The first end is pulled to tightenthe first knot with the second cable end being accessible to adjust thesize of the loop. The first end of the cable is then tied to the loopthrough a second non-self-loosening knot to create an opening in asecond portion of the cable which is placed around an object to be tied.The second cable end is pulled to reduce the size of the loop andtighten the opening around the object to be tied.

The flexible cable is formed of a braided polymeric material formed ofhigh strength, biocompatible, organic polymer, preferably polyolefinssuch as ultra-high molecular weight polyethylene.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention can be obtained when thedetailed description of exemplary embodiments set forth below isreviewed in conjunction with the accompanying drawings, in which:

FIG. 1 is a pictorial view of the load bearing cable of the presentinvention as applied to adjacent vertebrae in a spinal column fusion.

FIG. 2 is a pictorial view of the load bearing cable of the presentinvention as applied to repair of a fractured patella.

FIG. 3 is a pictorial view of the load bearing cable of the presentinvention as applied to the repair of a torn ligament.

FIG. 4 is a pictorial view of the load bearing cable of the presentinvention as applied to the repair of a clavicular ligament.

FIG. 5 is a longitudinal view of a braided load bearing cable of thepresent invention.

FIG. 6 is a pictorial view of a load bearing cable of the presentinvention swaged to a needle.

FIG. 7 is a side plan view of a human spinal column with a cableattachment apparatus of the present invention securing adjacentvertebrae together;

FIGS. 8-9 are top plan views of the formation of the firstnon-self-loosening knot of the present invention;

FIG. 10 is a top plan view of the present invention illustrating thefirst and second non-self-loosening knots;

FIG. 11 is a top plan view of the second non-self-loosening knot of thepresent invention;

FIGS. 12-14 are top plan views of the formation of an alternate firstnon-self-loosening knot of the present invention;

FIG. 15 is a top view of an alternate second non-self-loosening knot ofthe present invention;

FIGS. 16-17 are top plan views of the formation of a further alternatesecond non-self-loosening knot of the present invention;

FIGS. 18-20 are top and side plan views of steps for utilizing anembodiment of the present invention to stabilize adjacent vertebrae;

FIGS. 21-22 illustrate alternate embodiments of the present invention asused to connect specific bones together;

FIGS. 23-29 are schematic sequential views that illustrate a preferredmethod for creating an eye splice on the end of the cable portion of themethod of the present invention;

FIGS. 30-32 are schematic sequential views that illustrate a splicingmethod for use with the method of the present invention;

FIGS. 33-36 are schematic sequential views illustrating the method ofthe present invention; and

FIGS. 37-39 are schematic sequential views illustrating the method ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 through 6 illustrate the exemplary embodiments of a load bearingcable 10 of the present invention. Although the cable of the presentinvention is shown as connecting specific small bones and/or ligaments,the cable can also be used in the repair of other small bones and softtissues.

As shown in FIG. 5, the load bearing, braided cable 10 is formed of aplurality of biocompatible polymeric fibers wound as bundles of parallelfibers into yarns 11. Yarns 11 of from one to six ply are then woundinto strands 12. The strands 12 are then intertwined to form the braidedcable 10, for example, an eight-strand diamond braid. In a preferredembodiment, the polymeric fibers are bundled into yarns of approximately650 denier, the yarns are wound into 1 to 6 ply, and more preferably oneor two-ply strands, and the strands are braided into a single, hollow,plain 8-strand diamond braid. The braided construction allowsutilization of high strength fibers as individual units while providingnegligible bending resistance. Preferably, the resulting braid containsapproximately 9 to 13 ticks per inch.

In rope terminology, a plain braid is defined according to the number ofpicks per inch. A "pick" is defined as a crossing of one yarn bundleover another, with the number of picks counted across the longitudinalaxis. The greater number of picks per inch, the tighter the braid. Inthe preferred embodiment, a braid having approximately 9 to 13 picks perinch provides a flexible cable having a desired diameter of less than 3mm.

The fibers are formed of a high strength, biocompatible, organicpolymer, preferably polyolefins such as high strength polypropylene orultra-high molecular weight polyethylene. U.S. Pat. No. 4,413,110, toKavesh et. al, which is hereby incorporated by reference, describes oneprocess for the production of ultra-high molecular weight polyethylene(UHMWPE) fibers which have a high tenacity and a high tensile modulus.Any suitable means for providing UHMWPE will suffice.

Commercial embodiments of the polyethylene fibers described in theKavesh patent are known by the trademarks SPECTRA-900 and SPECTRA-1000and are sold by Allied-Signal, Inc. These commercially available fibershave a tensile strength of about 375,000-425,000 psi per individualmonofilament. The density of each monofilament is between 0.5 and 1.5g/cc, preferably about 0.97. Fibers of SPECTRA-1000 have a tenacity ofapproximately 35 g/denier, a specific gravity of 0.97 and an averagediameter of 27 microns (0.0011 inch). Each monofilament is less than 100microns in diameter. Fibers are assembled to form a tight weave whichdiscourages fibrous ingrowth. Preferably, pore sizes are less than 30microns. For UHMWPE, the cable 10 is optimally formed of 8 strands, eachstrand having from one to six ply. Each single ply strand containsapproximately 120 fibers of UHMWPE. Thus, the preferred embodiment ofthe braided load-bearing cable 10 has from 960 individual fibers for aone ply braid to 1920 individual fibers for a two ply braid.

Preferably the load bearing cables of the present invention have adiameter of approximately less than three millimeters and can carryloads of up to 550 pounds. For example, a single ply 8-strand diamondbraid can withstand a load of approximately 180 lbs. and a double plycan withstand a load of approximately 320 lbs.

The cables of the present invention are formed with the strongestavailable biocompatible polymer and optionally with a biocompatibleresorbable polymer. The upper limit imposed on the strength of thepolymer is the flexibility required.

In one embodiment, the polymeric fibers of the present invention arebioresorbable. Suitable fibers are, for example, those formed ofpolylactic acid or polyglycolic acid.

Examples of materials useful in the present invention are ultra-highmolecular weight polyethylene fibers, each having a tensile strength ofat least 350,000 psi. Especially preferred is the ultra-high molecularweight polyethylene, e.g., Spectra-1000. The surface of the fibers maybe modified, for example roughened, for ease of fixation of the cable.

The load bearing cable of the present invention may be utilized in avariety of surgical procedures to fuse or repair small bones andligaments and tendons. For example, the cable may be used as an orthosisand shield the torn ligament or tendon from the normal stress and strainuntil the tissue has healed, e.g. by sewing the cable through remnantsof a ligament and bringing the torn ends into opposition. To facilitatesuch use, the cable 10 may be attached to a needle 21 as shown in FIG.6, or similar device for threading the cable 10 through tissues.

Alternatively, the cable may be used to shield normal stress and strainuntil the tissue has become strong enough to carry the full amount ofstress, e.g. by sewing the cable through a replacement tissue graft. Theload bearing cable of the present invention may also be substituted forsurgical wire or cable in the repair of small bone fractures such as thepatella or bone fusions such as vertebral fusions. The cable hassufficient tensile strength to maintain bone fragments in closeapproximation to promote active healing and is sufficiently inelastic toprevent separation of fragments under tensile loading. The load bearingcable is less susceptible to fatigue failure than surgical wire. In theevent the cable does fail, no threat of damage to surrounding tissue isposed.

Characteristics of the structure of the present invention and itsapplication may be better understood by reference to the examples whichfollow:

EXAMPLE 1 FATIGUE TESTING OF METAL SURGICAL SUTURES

Titanium orthopedic cable having a diameter of 0.045 inch and cobaltchromium orthopedic cable having a diameter of 0.045 inch were testedfor bending fatigue. The titanium cable was Ti-6A1-4V (ASTM F-136) andthe cobalt chrome was ASTM F-90. A 15 inch length of the metal cable wasinstalled on a bending fixture for fatigue testing. A loading rod wasfixed to a load cell and the fatigue test fixture was positioned so thatthe loading rod was directly above the cable. Operating in strokecontrol the loading rod was moved downward against the cable until aload of two pounds was read. The displacement of the crosshead at thistwo pound load was recorded. The rod was then advanced until a load of20 pounds was indicated, and this displacement was recorded. Still instroke control, a sinusoidal function varying between the two previouslyrecorded displacements was established at a rate of 0.5 Hz. This createda load variation on from 2 to 20 pounds on the cable, with resultantbending around the rod. Testing continued until the cable broke. Thistesting was performed on six titanium cables and six cobalt chromiumcables. The results are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                        CABLE MATERIAL AVG CYCLES TO FAILURE                                          ______________________________________                                        COBALT CHROMIUM                                                                              18,408 (S.D. 4854)                                             TITANIUM        8,042 (S.D. 1161)                                             ______________________________________                                    

EXAMPLE 2 FATIGUE TESTING OF A COBALT-CHROME SURGICAL CABLE

Testing was performed on a cobalt-chrome surgical cable ASTM F-562(Richards MP35N), 0.044 inches in diameter in a bending fixture asdescribed for Example 1. The pulley system was cycled at a rate of 0.7Hz at displacements that resulted in the plunger seeing an axial loadthat varied between 2 to 20 pounds. Cycling was halted upon failure. Theaverage fatigue life was 56,700 cycles.

EXAMPLE 3 FATIGUE TESTING OF BRAIDED UHMWPE SURGICAL CABLE

An ultra-high molecular weight polyethylene braided cable was fabricatedfrom Spectra 1000™ fiber. Yarns of approximately 650 denier werearranged as single ply and two-ply strands, and braided into an 8-strandhollow diamond braid.

The braided cable was fatigue tested in a bending fixture as describedin Example 1. The springs had a spring constant of 6 lbs/in. The pulleyradius was one inch. The distance between pulley centers was threeinches. The load plunger had a radius of 0.2 inches. Each test wasconducted at 1 Hz.

During fatigue testing, the surgical cable or metal suture was subjectedto a sinusoidal plunger load of from 2-20 pounds-force (lbf). Thesprings provided resistance to the plunger load. The material was alsosubjected to a pre-load of approximately 7.5 lbf due to the tensioningof the springs.

The polymeric ultra high molecular weight polyethylene cable of thepresent invention was attached to the springs by tying a knot in bothends of the braid and searing the knot with heat. The knot was thenpassed through a ring and set screw and a set screw was tightened downto secure the braid to the spring.

Because the cable was flexible, the loading was considered a purelytensile load. Therefore, a static analysis was used to determine thetension in the cable. A single ply braid having a cross-sectionaldiameter of approximately 0.040 inches (1 mm) and a two-ply braid havinga cross-sectional diameter of approximately 0.060 inches (1.52 mm) weretested. The maximum stress in each cable was 401 psi for the single plyand 267 psi for the two ply cables.

Before testing, half of the ultra high molecular weight polyethylenebraids were treated to roughen the surface of the braid for enhancementof knot holding capability of the braid by application of a chargedplasma to the surface of the braid.

Five tests were run for each of the single ply and two ply braids inboth treated and untreated conditions. The results are shown in Table 2.The single ply and two ply braided ultra high molecular weightpolyethylene surgical cable in both treated and untreated conditionssurvived 100,000 cycles in the bending fixture described above. Therewere no braid failures or knot failures in any of the tests taken to100,000 cycles.

Fatigue testing of metal surgical cables using the same procedure andprotocol indicated that MP35N cables (cobalt-chrome) had a fatigue lifeof 56,700 cycles as discussed in Example 2. Testing of titanium andCo-Cr surgical cable using the same protocol and procedures determinedthe fatigue life to be 8,042 cycles and 18,408 cycles, respectively, asdiscussed in Example 1. These results indicate the braided polymericcable of the present invention has a better fatigue life than the metalcables formed of cobalt-chrome, or titanium. The charged plasma surfaceroughening treatment did not effect the fatigue life of the braid.

                  TABLE 2                                                         ______________________________________                                        FATIGUE STRENGTH OF UHMWPE BRAIDED CABLE                                                   ROUGHENING                                                       PLY          TREATMENT    CYCLES                                              ______________________________________                                        SINGLE       UNTREATED    100,000                                             SINGLE       UNTREATED    100,000                                             SINGLE       UNTREATED    100,000                                             SINGLE       UNTREATED    100,000                                             SINGLE       UNTREATED    100,000                                             SINGLE       TREATED      100,000                                             SINGLE       TREATED      100,000                                             SINGLE       TREATED      100,000                                             SINGLE       TREATED      100,000                                             SINGLE       TREATED      100,000                                             TWO-PLY      UNTREATED    100,000                                             TWO-PLY      UNTREATED    100,000                                             TWO-PLY      UNTREATED    100,000                                             TWO-PLY      UNTREATED    100,000                                             TWO-PLY      UNTREATED    100,000                                             TWO-PLY      TREATED      100,000                                             TWO-PLY      TREATED      100,000                                             TWO-PLY      TREATED      100,000                                             TWO-PLY      TREATED      100,000                                             TWO-PLY      TREATED      100,000                                             ______________________________________                                    

EXAMPLE 4 REPAIR OF ANTERIOR CRUCIATE LIGAMENT

The anterior CRUCIATE ligament of the knee connects the femur to thetibia, preventing the tibia from sliding anteriorly beneath the femur.As shown, for example in FIG. 3, to repair or reconstruct a tornanterior cruciate ligament, the load bearing cable 10 of the presentinvention is anchored to both the femur 13 and the tibia 14. Anchorageto bone may be via surgical staple, pins, or screws 15. The cable 10 issewn along the axis of the normal ligament, and thus bears all or partof the tensile load normally borne by the native ligament. The cablereplaces a cast, cast-brace or brace normally required to immobilize thejoint after surgery and permits healing of the tissue graft by acting asan internal splint to shield the tissue from stress while permittingsome joint motion during the post-operative period. This procedurealleviates loss of tensile strength in the tissue graft normallyassociated with joint immobilization following surgery. Oncesatisfactory tissue strength is achieved in the graft, the cable may beremoved.

When a bioresorbable cable is used to augment the ligament, the cablewill resorb over a suitable time for healing, gradually transferringload to the tissue graft.

EXAMPLE 5 REPAIR OF PATELLA FRACTURE

As shown in FIG. 2, the patella 16 is a small bone which covers theanterior compartment of the knee joint. Superiorly it is attached to thetendon of the quadriceps muscle group and interiorly, it is attached tothe patellar ligament 17, which inserts into the anterior surface 18 ofthe tibia 14. The patella 16 functions to enhance the lever arm of themuscles which extend the leg. As such, the patella 16 is loaded intension, having an approximate superior-inferior direction.

When the patella 16 is fractured in a transverse direction,perpendicular to the line of force, apposition of the patella fragmentsand compressive force is required to keep the fragments in closeapproximation for healing. Generally, surgical wire has been used tobend tightly around the patella 16, twisting two ends of a wire togetherto provide compressive force. This application method often results inwire breakage. In addition, post implantation wire fatigue caused byhigh tensile stresses from the quadriceps muscle group during extensionof the leg often causes surgical wire to fail. Failure of the wire toapply sufficient compressive force or failure or intimate apposition ofpatella fragments due to wire breakage results in a reduced or failedhealing of the bone. Sharp wire points caused by wire breakage in situcan result in significant damage to surrounding tissues and may evenpenetrate the knee joint capsule.

The load bearing cable 10 of the present invention is substituted forsurgical wire in repair of patella 16 fractures. The cable material iswrapped tightly around the patella 16 with two ends 19 tied togethertightly to provide compressive force. The cable 10 has sufficienttensile strength to maintain the patella fragments in closeapproximation and promote active healing, and is sufficiently inelasticto prevent separation of the patella 16 fragments under tensile loading.The load bearing cable is less susceptible to fatigue failure thansurgical wire. In the event the cable does fail, no threat of damage tosurrounding tissues is posed.

When the cable is formed of a bioresorbable polymeric fiber, stress willgradually be transferred to the patella in a controlled manner, as thecable is resorbed, enhancing healing per Wolff's law, bone remodels inresponse to applied stress.

EXAMPLE 6 FUSION OF SPINAL VERTEBRAE

Current procedures for repair or fusion of the spinal column restrictmotion of vertebral bodies by fixing posterior elements of thevertebrae, transverse processes and pedicles, together, inserting a bonegraft along the posterior surface of the spinal column, and then fixingthe graft into position. Satisfactory fusion requires that the vertebraeremain sufficiently immobilized to permit healing of the bone graft tothe vertebrae.

In general, surgical wire has been used in this procedure. Problems withthe use of surgical wire in spinal fusions are similar to thoseencountered with the patella fusion described for Example 5, includingwire breakage during insertion or tensioning, failure to maintainadequate compressive force, and fatigue of wire over time. In additionthe proximity of the spinal cord to the fusion site makes theconsequences of wire breakage life threatening.

These problems are circumvented by use of the load bearing cable of thepresent invention as described in Example 5. As shown, for example inFIG. 1, the surgical cable 10 of the present invention is substitutedfor surgical wire in the fixation of the posterior elements 20 of thevertebrae and fixation of the graft into position. The surgical cable ofthe present invention provides sufficient compression and tensilestrength to maintain the vertebral processes and/or graft in closeapproximation for fusion and healing.

When a bioresorbable fiber cable is used, stresses transferred to thebone graft in a controlled manner as the cable is resorbed, resulting inenhanced healing and greater success rate.

Having described the invention above, various modifications of thetechniques, procedures, material and equipment will be apparent to thosein the art. It is intended that all such variations within the scope andspirit of the appended claims be embraced thereby.

In FIGS. 7 and following present invention provides a cable attachmentapparatus 25 for the surgical repair or fusion of anatomical structures.FIG. 7 illustrates a cable attachment apparatus 25 being used tostabilize adjacent human vertebrae V of a human spinal column S. Thecable attachment apparatus 25 (FIG. 8) is constructed from a length offlexible cable 26 formed of braided polymeric material. The cable 26 hasa central portion 27, first and second end portions 28, 30 and first andsecond cable ends 29, 31.

A first adjustable loop 37 is formed in a portion of the cable 26 bytying a first non-self-loosening know 32 which is capable of beingadjusted by pulling the cable end portion 29 (FIG. 9). The firstadjustable loop 37 is formed with the end portion 30 of the cable 26 bytying a first non-self-loosening knot 32 which is capable of beingadjusted by pulling the end 29 of cable end portion 28 in order toreduce the circumference of the first loop 37.

In FIG. 9, the first loop 37 can be formed using knot 32 which issimilar to a clinch knot, for example. Clinch knots per se are known,being used most commonly in the prior art by fishermen to securemonofilament line to a fish hook eye. Published literature describes theprocedure for tying a clinch knot. Variations of a clinch knot are inpublished literature of fishing line manufacturers, e.g., BerkleyOutdoor Technology Group of Spirit Lake, Iowa (Berkley describes a knotin its literature as the "Trilene Knot"). Knot 32 can be formed bymaking several turns 34 (e.g., five (5) turns) of the end 30 of the line26 around the central 27 part of the line 26. In FIG. 9, the tag end isfree end 30 and the standing part is end portion 29. The five (5) turnsare shown as twists 34 in FIG. 9. The end portion 30 is inserted throughthe loop 37 (see arrows 35, 36) forming a temporary loop 37. The endportion 30 is then inserted through the just formed temporary loop (seearrows 39, 40) and tightened by pulling the portion 30 to closetemporary loop 38. The completed knot 37 is shown in FIG. 10.

A second adjustable loop 41 is formed in portion 27 of the cable forthreading around or through an anatomical structure or other objectdesignated schematically as anatomical structure 45 (FIG. 10). The loop44 is tied to the loop 37 with a second non-self-loosening knot 33. Theknot 33 is formed after the loop 41 has been secured around or throughthe structure 42 to be tied.

The braided polymeric cable 26 is made of fibers formed of a highstrength, biocompatible, organic polymer, preferably polyolefins such asultra high molecular weight polyethylene. In a preferred embodiment thecable 26 is formed of Spectra-1000 and the cable attachment apparatus 25can be formed of braided polymeric cables of a variety of diameters.

The invention is also directed to a method of forming the cableattachment apparatus 25. The cable attachment apparatus 25 isconstructed from the length of flexible cable 26 (FIG. 8) by forming afirst adjustable loop 37 by wrapping the cable end 30 around a portionof the cable 28, between the first and second cable ends 29, 31, aplurality of turns 34 as illustrated in FIG. 9. The cable end 30 ispassed through the loop 37 to create a second loop parallel to theplurality of twists 34 (FIG. 9). Cable end 30 is then passed backthrough the temporary loop 38 and tightened to create thenon-self-loosening knot 32 as shown in FIGS. 10 and 17.

The cable end 29 is then threaded around or through the object to betied, forming a second adjustable loop 41. After the cable end 29 isthreaded around or through the object, the end 29 is tightened to reducethe slack in the loop 37 and tied to the loop 37 with anon-self-loosening knot 33. The non-self-loosening knot 33 is formed bypassing the cable end 28 through the loop 37 at least one turn, on theside of the loop 36 opposite the non-self-loosening knot 32, and forminga plurality of half hitches 41 (FIG. 11) between the cable end and aportion of the cable (FIGS. 10 and 19).

As illustrated in FIG. 11, the half hitches 43 are formed by passing thecable end 29 through the loop 37, looping cable end 29 under and aroundthe loop portion 37, then looping the end 29 again under and around theloop portion 37 forming a second half hitch, and pulling the cable end29 taut to create the non-self-loosening knot 33.

The cable end portion 30 is then tightened to reduce the size of theloop 37 which causes the cable attachment apparatus 25 to be tensionedand securely held around or through the object being tied.

As illustrated in FIGS. 12-14, an alternate method of forming theadjustable loop is by positioning the two portions 44, 45 of the cable12 between the first and second cable ends 28, 30 parallel to each other(FIG. 12). A temporary loop 46 is formed (FIG. 13). The cable end 31 isthen wrapped around the two parallel portions 44, 45 and through thetemporary loop 46 to form a plurality of turns 47 and tightened tocreate the non-self-loosening knot 48 (FIG. 14). Alternately, anon-self-loosening knot 49 can be formed by passing the cable endthrough loop 50 at least three times, forming loops, and then tying afisherman's bend knot between the cable end and a portion of the loop onthe side of the loop opposite the knot. The fisherman's bend knot isillustrated in FIG. 6 and is formed by passing the cable end 31 aroundthe loop 50 a plurality of times forming loops 51, 52. The cable end 31is brought down over the end portion and up through the loops 51, 52 andthen a second half hitch as described above is formed.

Another method of forming the non-self-loosening knot is shown in FIGS.16-18. A clinch knot 53 is formed by first passing the cable end 29through the loop 54 and then wrapping end 29 around a portion of loopend 30 a plurality of turns 55. The cable end 29 is next threaded upthrough the loops 56 (see arrows 58) (FIG. 16) forming a loop 57 andthen back down through (see arrows 59) loop 57 and tightened (FIG. 17).

In an alternate embodiment of the cable attachment apparatus designatedas 60, the loop 61 and knot 62 are preformed. Cable attachment device 60is shown in FIG. 18 having a preformed adjustable loop 61 and apartially tightened non-self-loosening knot 62. A blunt tipped needle 63is attached to the cable end 26 so as to allow easier threading of thecable end 14 around or through the object to be tied. The needle can becurved or straight and after the cable attachment device 60 is tensionedand secured in place the needle 63 is removed from the cable end.

An example of the cable attachment device 60 being used to stabilizeadjacent vertebrae is illustrated in FIGS. 19-20. The preformed loop 61of the device 60 is placed along side one of the vertebrae V to bestabilized. The cable end with the needle 63 is wrapped around theadjacent vertebrae V forming the loop 64. The needle 63 is then threadedthrough the loop 61 and the cable end 19 is tightened in order to removethe slack in loop 64 (FIG. 19). The non-self-loosening knot 62 is tiedand the cable end is tightened in order to tension and secure the cableattachment device 60 around the adjacent vertebrae.

The cable attachment apparatus 10 can be used for the surgical repair orfusion of anatomical structures and for use as a securing device innon-medical applications. For example, the cable attachment apparatuscan be used for the repair of fractures or fusions of any small bones,it can be used to hold together fragments of the patella or in therepair of tendons and ligaments such as those found in the clavicle. Thecable attachment apparatus can also be used wherever wire, heavy suturesor staples are used in a medical procedure. For example, in trochantericreattachment procedures the cable apparatus can be used in place ofmonofilament wire (FIG. 21).

FIGS. 23-29 illustrate a method for creating an eye splice on an end ofa length of cable 70 opposite a surgical needle. In FIG. 23, a desiredlength of cable 70 is shown having sewing needle 71 attached at it eye72 to end 73 of cable 70. Cable 70 can be provided with marks 74-77 atintervals of for example 1 inch, 2 inches, 2.5 inches, 3.5 inches fromthe end 73 of cable 70.

The user passes the end 73 of the cable 70 and sewing needle 71 throughthe middle of the cable 70 at the third mark 76 (see FIG. 23). The end73 of cable 70 is then pulled through until the second mark 75 passes tothe cable. This produces a small eye 78 as shown in FIG. 24. The cablenow has a short section (tail) 79 and a long section (standing line) 80.The long section 80 has a surgical needle 81 attached thereto (see FIG.25). The user then holds the eye 78 just constructed and threaded thelong 80 section of cable 70 (with the surgical needle 81 attached)through the short end 79 at a position adjacent the eye 78 as shown inFIG. 25. In FIG. 26, the user then pulls the long 80 end until no moreslack exists. The short end 79 of cable 70 is then buried by placing thesewing needle 71 through the center of the cable adjacent the eye 78.The sewing needle 71 should exit the cable of few picks past the lastmark 77. Scissors can be used to cut off any excess at the end 73. Thestanding line 80 is then pulled to insure that the end of the tail 79 isburied in the middle of the cable as shown in FIG. 29.

FIGS. 30-36 illustrate the method of the present invention using the eyesplice, cable and needle constructed in FIGS. 23-29.

In FIGS. 30-32, a splicing technique is shown. The surgical needle 78 ispassed through the eye 78 and then through the center of the cable 70 atposition 82 in FIG. 30. This step is repeated three more times for atotal of 4 moving away from the loop end 78 as shown in FIG. 31. In FIG.31, the needle passes through the cable at positions 82-85, formingloops 86-89. A tensioner can be used to tighten the knot, but is notnecessary. The knot can be tightened without such a tensioner. If atensioner is to be used, the needle is placed through a hole in the tipof a tensioner shown in FIG. 32 then through the latch in the center ofthe tensioner. The cable is then tightened with the tensioner and thecable 70 and needle removed from the tensioner. As a last optional step(see FIG. 31A), the needle 81 can be used to pass the needle end of thecable 70 through the tightened knot.

FIGS. 33-36 illustrate surgical technique using the cable, needle andsplicing that is shown and described in FIGS. 23-32. In FIG. 33, thecable 70 is doubled at its central portion and passed underneath thearch of vertebrae C1, designated as C1 in FIG. 33. A loop 90 is formedwhen the cable is doubled, in FIG. 3 the loop can be seen after passingunderneath the arch of C1.

In FIG. 34, the loop 91 has been wrapped around the spinous process ofC2. At this point, the surgeon places bone graphed material designatedas 91 in FIG. 35. After the bone graph material 91 has been placedbetween C1 and C2, the surgeon then passes the surgical needle 81through the eye 78 as shown by arrow 93 in FIG. 35. In FIG. 36, thesurgeon then wraps the cable 70 over the bone graph 92 and underneaththe spinous process of C2. The cable is then secured using the splicingtechnique described with reference to FIGS. 30-32.

FIGS. 37-39 illustrate the surgical technique using the cable needle andsplicing that is shown in and described in FIGS. 23-32. In FIG. 37, theneedle 81 and cable 70 are passed through a hole that has been drilledthrough the spinous process. In FIG. 38 a piece of bone graft material Bhas been inserted between the two adjacent spinous processes. After thebone graft material is placed between the spinous processes, the cable70 is wrapped around the adjacent spinous process and the surgicalneedle 81 is passed through the eye 78. The cable 70 is then tightenedaround the spinous processes (FIG. 39) and secured using the splicingtechnique described with reference to FIGS. 30-32 and 31A.

This splicing fixation technique of FIGS. 23-39 may be used in the sameapplications as the techniques shown in FIGS. 7-22. In particular it isideally suited for use in spinal fusions, olecranon fracture repair,patellar fracture repair, trochanteric reattachment, tendon and ligamentreattachment, acromioclavicular (AC) joint repair, rotator cuff repairs,ceriage and other general orthopaedic repair procedures.

It should be understood that there can be improvements and modificationsmade to the embodiments of the invention described in detail abovewithout departing from the spirit or scope of the invention, as setforth in the accompanying claims. The following table lists the partsnumbers and parts description as used herein and in the drawingsattached hereto.

    ______________________________________                                        PARTS LIST                                                                    Part Number     Description                                                   ______________________________________                                        10              load bearing cable                                            11              yarns                                                         12              stands                                                         12a            axis                                                          13              femur                                                         14              tibia                                                         15              screws                                                        16              patella                                                       17              patella ligament                                              18              anterior surface                                              19              ends                                                          20              posterior elements                                            21              needle                                                        V               vertebrae                                                     S               spinal column                                                 25              cable attachment apparatus                                    26              flexible cable                                                27              central portion                                               28              first end portion                                             29              first end                                                     30              second end portion                                            31              second end                                                    32              non-self-loosening knot                                       33              non-self-loosening knot                                       34              twists                                                        35              arrow                                                         36              arrow                                                         37              first adjustable loop                                         38              temporary loop                                                39              arrow                                                         40              arrow                                                         41              second adjustable loop                                        42              anatomical structure                                          43              half hitch                                                    44              cable section                                                 45              cable section                                                 46              temporary loop                                                47              turns                                                         48              knot                                                          49              knot                                                          50              loop                                                          51              loop                                                          52              loop                                                          53              clinch knot                                                   54              loop                                                          55              turns                                                         56              loop                                                          57              loop                                                          58              arrow                                                         59              arrow                                                         60              cable attachment                                              61              loop                                                          62              knot                                                          63              needle                                                        64              loop                                                          70              cable                                                         71              needle                                                        72              eye                                                           73              end                                                           74              mark                                                          75              mark                                                          76              mark                                                          77              mark                                                          78              eye                                                           79              tail section                                                  80              standing line                                                 81              needle                                                        82              position                                                      83              position                                                      84              position                                                      85              position                                                      86              loop                                                          87              loop                                                          88              loop                                                          89              loop                                                          90              tensioner                                                     91              loop                                                          92              bone graft                                                    93              arrow                                                         C1              vertebra                                                      C2              vertebra                                                      ______________________________________                                    

What is claimed is:
 1. A method for the fusion of bone segments havingouter surfaces, comprising the steps of:a) positioning the bone segmentsinto close approximation with each other; b) providing a surgical cablehaving a needle at one end of cable, the cable being formed of aplurality of polymeric fibers to force the opposed bone segments towardeach other, the polymeric cable having two free ends and being of adiameter of between one and three millimeters (1-3 mm) along the entirelength thereof including said ends, to define an elongated thin cablewith sufficient inherent flexibility for enabling the cable to bewrapped around the bone segments, said cable having fibers withsufficient tensile strength so that the cable is capable of bearingstress loads to allow the fusion of the said opposing bone segments andto be sufficiently inelastic so as to maintain continuous pressure onthe bone segments; c) wrapping the cable around the bone segments; d)applying a compressive force to the adjacent bone segments; e) securingthe cable in place relative to the bone segments by splicing the cableends together using the needle during said splice of the cable byweaving the needle through the cable; and f) minimizing stressconcentration at the bone segment outer surfaces by closely conformingthe cable to the outer surfaces of the bone segments.
 2. The method ofclaim 1, wherein the cable having a diameter of 3 millimeters or lesshas a tensile strength of generally 310,000 psi which provides a loadbearing capacity of about 1600 pounds.
 3. The method of claim 1, whereinthe opposed bone elements includes adjacent vertebrae of a spinalcolumn.
 4. The method of claim 1, wherein the polymeric cable is formedfrom a plurality of polymeric fibers with the tensile strength of eachpolymeric fiber being greater than 350,000 psi.
 5. The method of claim1, wherein the cable has a diameter of 3 millimeters or less with atensile strength f generally 310,000 psi which provides a load bearingcapacity of about 1600 pounds.
 6. The method of claim 1, wherein thepolymeric cable is formed of braided strands of polymeric fiber.
 7. Themethod of claim 1, wherein the polymeric material is formed of ultrahigh molecular weight polyethylene fibers.
 8. The method of claim 1,wherein the polymeric fibers are formed of Sprectra 1000™.
 9. The methodof claim 1, wherein the polymeric material is biocompatible.
 10. Themethod of claim 1, wherein the step of securing the cable furtherincludes knotting the ends of the cable together.
 11. The method ofclaim 1, wherein the step of securing the cable further includes fusingthe ends of the cable together with heat.
 12. The method of claim 1,wherein the step of securing the cable further includes attachment tobone with an attachment means, the attachments means is selected fromthe group consisting of surgical staples, pins, and screws.
 13. A methodfor the fusion of vertebrae of a spinal column, comprising the stepsof:a) providing a surgical cable having a needle at one end of thecable, the cable being formed of a plurality of polymeric fibers toforce the vertebrae toward each other, the polymeric cable having twofree ends and being of a diameter of between one and three millimeters(1-3 mm) along the entire length thereof including said ends to definean elongated thin cable with sufficient inherent flexibility forenabling the cable to be wrapped around the vertebrae fragments, saidcable having fibers with sufficient tensile strength, so that the cableis capable of bearing sufficient stress loads to allow the fusion ofadjacent vertebrae; b) wrapping the cable around the vertebrae; c)applying a compressive force to the adjacent vertebrae; d) securing thecable in place relative to the vertebrae by splicing the cable endstogether using the needle during said splice of the cable by weaving theneedle through the cable; and e) minimizing stress concentration byclosely conforming the cable to the outer surface vertebrae.
 14. Themethod of claim 12, wherein the polymeric cable is formed from aplurality of polymeric fibers having a diameter of less than or equal to3 millimeters with the tensile strength of each polymeric fiber being noless than about 350,000 psi.
 15. The method of claim 12, wherein thepolymeric cable is formed of braided strands of polymeric fiber.
 16. Themethod of claim 12, wherein the polymeric material is formed of ultrahigh molecular weight polyethylene fibers.
 17. The method of claim 12,wherein the polymeric fibers are formed of Spectra 1000™.
 18. The methodof claim 12, wherein the polymeric material is biocompatible.
 19. Themethod of claim 12, wherein the step of securing the cable furtherincludes knotting the ends of the cable together.
 20. The method ofclaim 12, wherein the step of securing the cable further includes fusingthe ends of the cable together with heat.
 21. The method of claim 12,wherein the step of securing the cable further includes attachment tobone with an attachment means, the attachment means is selected from thegroup consisting of staples, pins, and screws.
 22. An orthopedicsurgical method of securing multiple bone parts of a patient togetherwith a cable attachment apparatus that includes a length of flexiblecable formed of braided polymeric material having first and second cableends, comprising the steps of:a) forming a first loop at the first cableend; b) encircling a plurality of selected bone structures with thesecond loop; c) attaching the second end to the cable through the firstloop to form a second loop; d) pulling on the first end through thefirst loop to reduce the size of the second loop to tighten the secondloop around the selected bone parts; and e) secure the loop and cable inthe tightened position by weaving the cable through itself.
 23. Themethod of claim 22, wherein the strands of polymeric cable includesfibers formed of a high strength, biocompatible, organic polymer,preferably polyolefins such as ultra-high molecular weight polyethylene.